1. Field of the Invention
Aspects of the present invention relate to a method of creating and managing a session between a wireless universal serial bus (USB) host and a wireless USB device, and provide the wireless USB host and the wireless USB device.
2. Description of the Related Art
Conventionally, a wireless universal serial bus (USB) technology is referred to as a certified wireless USB (CWUSB). An operation of connecting a wireless USB host and a wireless USB device generally includes a certification operation, a reconnection operation, a connection close operation, and a sleep/wakeup operation for power management.
The CWUSB uses an ultra-wideband physical layer (UWB PHY) and is based on a time division multiple access (TDMA). Accordingly, a time scheduling by the wireless USB host is needed such that the wireless USB device can transmit data to the wireless USB host in an allocated time slot. An adaptability of the CWUSB is reduced when dependent on a single wireless technology since mobile devices that apply the wireless USB technology use various wired/wireless networking technologies.
Moreover, a session connection operation in a session management method of the CWUSB is only started by the wireless USB device. In this case, a usage scenario that can be used by a practical user and the conditions of the wireless USB device that can apply to the CWUSB may be limited. For example, when a single wireless USB device must select a single conceptual association from among several possible conceptual associations, the single wireless USB device displays the conceptual associations and requires a navigation button to select the single conceptual association. However, not all devices employing the wireless USB technology have the navigation button. Therefore, in this case, the role of the wireless USB device must be minimized, while most of the roles must be performed by the wireless USB host.
Furthermore, when the wireless USB device transmits a connection request and the wireless USB host does not respond thereto, the wireless USB device must retransmit the connection request. Unlike a USB connection in a wired method where power is supplied from the wireless USB host, the wireless USB device using the CWUSB must include a power supply (such as a battery). Therefore, the operation of retransmitting the connection request increases the battery consumption of the wireless USB device.
Finally, when a momentary loss of connection occurs due to wireless network characteristics, a reconnection operation must be performed. As a result, the load on the wireless USB device may be increased. Moreover, an operation of recognizing the wireless USB device by an operating system has to be performed for every reconnection operation, thereby causing inconvenience to the user.